Gas modulating valve control



April 20, 1954 P, SCHELL 2,675,965

GAS MODULATING VALVE CONTROL Fled Feb. 2, 1952 2 Sheets-Sheet 2 IN VEN TOR.

Patented Apr. 20, 1954 GAS MODULATING VALVE CONTROL Paul Schell, Elkhart, Ind., assignor to Penn Controls, Inc., Goshen, Ind., a corporation of Indiana Application February 2, 1952, Serial No. 269,624

6 Claims.

This invention relates to a gas modulating valve control and particularly one of the type which effects the operation of a combined on-oif and modulating valve used as a controlling means between a source of gas or other fuel and a burner in a furnace or the like for heating a room.

One object of the invention is to provide a pilot control arrangement for' a gas actuated diaphragm type of modulating valve which includes an electrically operable modulating means for the main valve and a pilot valve arrangement for opening and closing the main valve at the beginning and end respectively of a modulating cycle. Another object is to provide a modulating valve structure which performs vthree functions: (l) ameans for turning on and off the supply of fuel to a burner or the like; (2) a means for modulating the iiow of the fuel after it has beenturned on; and (3) a means for adjusting the minimum flame, the arrangement being such that functions (l) and (2) are handled entirely by a single electrically operated heat motor act/ing first on a pilot valve and secondly acting directly on the main valve to modulate it.

Still another object is to provide a modulating valve control arrangement'wherein a diaphragm actuated valve is under control of both a pilot valve and an electric means for'modulating the valve, the pilot valve being under control of the electric means for opening and closing the valve and the electric means performing the modulation of the valve after it is opened and untilsuch time as it is closed, the electric means in turn being controlled by a modulating room thermostat or other condition responsive mechanism.

A further object is to provide an electrically operated pilot valve which is operated by a modulating device so as to open a main gas valve when the modulating mechanism begins a call for heat and to close it when the heat demands are satised.

Still a further object is to provide a combined modulating and cut-olf valve device including pressure motor means, pilot control means operable in response to room temperature changes to open the valve device at a predetermined temperature when the temperature is dropping, and power means for modulating it when the room temperature is below the predetermined temperature, the power means modulating the valve device in accordance with room temperature after it is opened and the pilot control means again closing the valve device when the room thermostat responds again to the predetermined temperature but when it is rising,

An additional object is to provide modulating means for the valve device comprising a thermostatic motor which includes a heating coil, a room thermostat controlling the input to the heating coil and including a heater in series therewith and means responsive to heat from the heater for separating the contacts of the room thermostat whereby it acts as a modulating thermostat.

Another additional object is to provide means for controlling the pilot valve comprising contacts operated by the thermostatic motor to be closed when the room thermostat calls for heat and to remain closed as long as the motor is operating in the modulating range and thereby modulating the valve device in accordance with the demand for heat affecting the room thermostat.

A further additional object is to provide a modulating control for fuel flow to heating means comprising pressure motor means including a movable Wall having a chamber on each side thereof, a pilot valve controlling pressures affecting the movable wall, a main fuel flow passageway sealed by the movable wall, a pair of spaced valve seats in the passageway, one of which constitutes a modulating valve seat and the other of which constitutes an on-oif valve seat, and means operated at one of its limits of. operation to actuate the pilot valve to effect opening of the on-off valve as the modulating motor moves away from the minimum modulated position and to eiect closing thereof as it returns to minimum modulated position.

With these and other objects in view, my invention consists in the construction, arrangement .and combination of the various parts of my gas modulating valve control, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawings, wherein:

Figure 1 is a plan view of my gas modulating valve control, parts thereof being broken away and other parts being shown in section to show details of construction.

Figure 2 is a vertical sectional view on the line 2 2 of Figure l, the lower part of the valve structure being shown in elevation.

Figure 43 is a vertical sectional View on the line 3-3 of Figure 1, a room thermostat circuit being shown diagrammatically in connection therewith.

Figure 4 is a diagrammatic view showing the parts in a different position than that assumed in Figure 3; and

Figure 5 is a diagrammatic view similar to Figure 4 showing the parts in still a different position.

On the accompanying drawings I have used the reference numeral i2 to indicate a valve body having an inlet lil and an outlet i6, the inlet adapted to receive gas and the outlet to be connected with a burner such as one in a residential Illllace.

The valve body l2 has an on-of valve seat I8 and a modulating valve seat 28. Within the valve body, an on-ofi valve closure element 22 is provided and a modulating valve element 24 is illustrated for coaction with the seats i8 and 20 respectively. The valve elements 22 and 2t are connected together for simultaneous movement by means of a stern 23 and a sleeve 25, and the valve element assembly, consisting of the elements 22, 23, i4 and 25, is connected with a valve operating diaphragm 26.

My valve structure also includes a sealing diaphragm 28 for a diaphragm cover 29 which cover in conjunction with the upper surface of the diaphragm 2S provides a pressure chamber 36.

Mounted on the valve body i2 and the diaphragm cover 29 thereof is a housing 6| and a pilot valve for operating the main valve to on and ofi positions. The pilot valve comprises a valve body 32. A pilot valve inlet seat 34 and a pilot valve bleed seat 36 are mounted in the valve body 32. A pressure supply tube 38 connects `the inlet side of the valve body i2 with the pilot valve inlet seat 34, fittings Li@ and i2 being provided at the ends of the tube 38 for this purpose. As shown in Figure 3, a port to the pressure supply tube 38 is provided to introduce the incoming gas pressure to the tube 38. Communication between the interior of the pilot valve body 32 and the pressure chamber Si! is provided by a port 46.

The pilot valve 32--36-'56 further includes a pilot valve blade fis and has a valve closure element 4S adapted to operate between the inlet seat 34 and a bleed seat 36 with snap action as will hereinafter appear. The upper end of the blade 48 is provided with a pair of shoulders 50 which are seated in a pair oi V seats 52 of a bracket 54.

A pilot valve actuating bimetal 55 is provided anchored as at 58 to the bracket 54 and provided on its lower end with a nger iii). Opposing the ringer 68 is a finger 62 on the pilot valve blade 48 as shown in Figure 3. A toggle 64 in the form of a tube is provided with J seats on its upper and lower ends as shown in Figure and the lingers 663 and 62 enter the tube with shoulders adjacent the ngers seated in the V seats whereby snap action is imparted to the blade 48 upon oscillation of the bimetal 56.

For producing such oscillation, the bimetal B is sprung to normally be in the position of Figure 2. When heated, it will swing toward the left as indicated by the arrow h as to the position shown in Figures i and 5, whereupon the toggle tube 64 will be reversed in its inclination and the pilot valve closure element 'lis will unseat from the bleed seat 3S and seat on the inlet seat 34 as shown in these two gures.

For operating the main valve, with respect to its modulating valve element 24 in relation to the modulating valve seat 20, I provide an electrically operable heat motor in the form of a modulating valve actuating bimetal 88. This bimetal carries a contact f for coaction at times with a contact i2 mounted on an actuating blade I4 of insulation material. The blade 'i4 is pivoted at 'I6 as by means of a leaf spring and at its opposite end. carries an actuating pin 18 adapted to coact through the diaphragm 28 with the upper end of the stem 23 as shown in Figures 4 and Normally the bimetal B8 is in the elevated posiM tion of Figure 3 with the contact 'i8 out of engagement with the Contact 12 and the upper end of the actuating pin 18 stopped against a stop Se which is adjustable for minimum flame when the main valve is modulating. The stop Sii is in the form of a screw threaded in a bracket 82.

For warping the bimetal element 68 dov/nwardn ly in response. to heat as indicated by the arrow 7i crossing the bimetal in Figure 3, I provide a heating element 84. Supply wires 86 and 8B supply current therefor through a room thermostat The wire 86 also connects with the contact l2; Whereas the contact 18 is connected by a wire 9:8 to the heating element 66 for the bimetal blade 58 of the pilot valve whereby the heating element of the pilot valve is under control of the contacts 10 and 12.

A wire 92 leads from the right hand end ci the heating element 84 in Figure 3 to a heater se in the room thermostat RT, the room thermostat having an auxiliary bimetal 06 responsive to the heater S4. The auxiliary bimetal carries a contact 88 for cooperation with a contact 5% carried by the main bimetal |02' of the room thermostat, which latter bimetal is the one responsive to room temperature.

Practical operation With the room thermostat RT satisfied and therefore the contact |00 separated from the contact 88, the parts will be in the position shown in Figure 3. The bimetal 68 will be cold and there fore its contact 10 will be separated from the contact 12. Accordingly, the heating element 6c therefore the birnctal 56 will be cold, as a result of which the pilot valve will be in the position shown in Figure 2 with the bleed seat 36 closed by the valve closure element 49 and the inlet seat 34 open. The gas pressure through the pressure tube 38 has charged the pressure chamber for holding the valve closing element 2'?. on the on-oi seat I8 because of pressure in the chamber 30 predominating that below the diaphragm 2e, the latter having less area because of the valve seat I8.

A5 the room temperature lowers, the Contact |00 of the room thermostat RT will eventually engage the contact 98 whereupon a circuit is established in the heater 84 for the bimetal 68. This current also passes through the heater` 13 of the room thermostat and warps the bimetal element S6 in the direction of the arrows so as to separate the contact 98 from the contact |00. Continued reduction in room temperature, however, causes the contact |00 t0 keep moving toward the right and there will accordingly be increments of electrical energization of the heating element 84 which cause the bimetal element 68 to continue to warp downwardly7 and inalre contact of 10 with l2 whereupon a circuit is established through the pilot valve heater 655. Since the burner is not yet in operation, the room temperature will continue to lower and the bimetal element 68 will likewise continue to move downwardly, carrying with it the actuating pin 18.

Within a short period of time, the heating elen ment 66 will have heated the bimetal element 56 suiciently for the toggle 04 to snap from the position of Figure 2 to the position of Figure 4, thereby closing oil the pressure from the tube 38 to the pressure chamber 30 andinstead permitting the pressure to be bled lout of the chamber 30 through the bleed seat 36, This seat is connected as by means of a tube 31 to the burner chamber for discharging adjacent the burner so that the gas from the tube will be burned. Pressure under the diaphragm 26 will raise the valves 22 and 24 and as soon as 22 leaves the seat I8, the effective diaphragm area is increased so that the valve 22 will move rapidly to the wide open position shown in Figure 4, thus moving the valve element 24 to a position adjacent the modulating seat 26. It is stopped, however, by the stop 26 as in Figure i which gives a minimum opening of the modulating valve 23-24 for minimum flame at the burner so that it burns at a low llame but with complete combustion. rIhe main valve thus passes from completely closed position through the Wide-open position to a minimum modulated position.

As the room thermostat RT continues to call for heat, the bimetal 96 of the thermostat, will warp toward the right as in Figure 5 under the action of the increments of energization in the heater 34 and the continued increments of energization thereof will cause the bimetal lit to ccntinue to warp downwardly as in Figure 5 to a modulated position such as that shown by solid lines. Thereafter the main valve will bemodulated (the valve element 24 relative to the modulating seat 20) depending on room temperature requirements. The auxiliary bimetal 9S is heated 'by the heater 94 so as to cause the 'control circuit to cycle with a speed dependent upon the position of the room temperature responsive bimetal H12. Further demand for heat by the room thermostat after 22 is unseated from I 3 increases the heat in the heater -84 and causes the binietal 5S to open the valve `22 from the minimum modulated position to a position corresponding to the demand as indicated by the room thermostat. Any lessem'ng of the value of heat demanded by the thermostat; reduces the heating eiiect on the bimetal 68 causing it to move toward the minimum modulated position. A further reduction in demand finally opens the circuit at '50* 7:2 allowing the pilot valve to eiect closing oi completely of the main valve.

The modulating valve structure disclosed performs three functions: (l) a means of turning on and oi the supply of fuel; (2) a means for modulating its flo-w after it has been turned on; and (3) a means for adjusting the minimum name. Functions (l) and (2) are handled entirely by the one bimetal 68 acting rst on a pilot valve and` secondly on the main valve to modulate it.

Describing the operation in greaterl detail, if the room temperature continues to drop during the modulating cycle of the main valve, the bimetal element 68 will continue to Warp downwardly and finally reach the maximum open position of 24 with respect to 2i! shown in Figure 5 with the actuating blade 'E4 against a maximum stop l5 as shown by dotted lines in Figure 5.

As the room temperature rises due to the operation of the burner, the increments of energization will be less in a given period of time, and/or of shorter1 duration, thereby permitting the bimetal element 68 to seek a higher level which results in the valve 24 modulating in a closing direction.

Finally when the room thermostat is satisiied to such an extent that the main valve returns to the position of Figure 4 with the actuating ducing pressure through the pressure tube 38 to the pressure chamber 3G for closing the main valve again to the position of Figure 3 where it remains until there is another call for heat by the room thermostat.

Some changes may be made in the construction and arrangement of the parts of my gas modulating valve control, without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims anyV modifled forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim as my invention:

l. A modulating main control valve for supplying gas to a burner, said valve having an on-oi seat, an on-off valve disk to seat thereon toward the gas inlet, and a modulating valve disk, a pilot valve for said control valve having a bleeder line, said control valve including a diaphragm responsive on one side surrounding said on-o seat to the inlet gas pressure, a pressure chamber on the other side thereof, said pilot valve being operable to admit gas pressure to said pressure chamber or connect the same with said bleeder line for respectively closing said valve at said on-o seat or opening the same, means for modulating said modulating valve disk in accordance with room temperature after said on-ofi valve disk is opened comprising a thermostatic motor therefor, said thermostatic motor including a heating coil, a room thermostat for controlling the input to said heating coil, said room thermostat including a heater in series therewith and means responsive to heat from said heater and including a contact movable thereby in relation to a second contact controlled by the room temperature responsive element of the room thermostat for separating said room thermostat contacts and repositioning them in joint response to said means and said room temperature responsive element, and means for controlling said pilot valve comprising contacts operated by said thermostatic motor to be closed when said room thermostat calls for heat and to remain closed as long as said thermostatic motor is operating in the modulating range.

2. A modulating control for fuel flow to heating means comprising pressure motor means including a movable wall having a chamber on each side thereof, a main fuel now passageway sealed by said movable wall, a pair of spaced valve seats in said passageway, one of which constitutes a modulating valve seat and the other of which constitutes an on-oil valve seat, a unitary valve structure operated by said pressure motor means and including a modulating valve and an on-off valve cooperating respectively with said modulating valve seat and said on-ci valve seat, said valve seats constituting ports arranged in series for the fuel flow. said valves simultaneously moving in alternate directions to perform their respective functions of modulation and cutoff, said movable wall being subject on one side surrounding said on-off seat to the line pressure and on its other side to either the line pressure or atmospheric pressure to close or open the valve at said on-off valve seat, means operated in response to variations in predetermined external conditions for adjusting said pressures for opening said valve at said on-off seat and for thereafter modulating said valve at said modulating seat, and means for causing the pressures on opposite sides of the movable wall to approach equality to an extent suiicient for said movable wall to close said valve at said on-off seat after said predetermined external conditions are satised.

3. A combined modulating and cut-oil valve device for fuel line to a burner comprising pressure motor means having a first chamber and a second chamber divided by a movable wall, a pair of spaced valve seats forming ports arranged in series for the fuel flow, a modulating valve for the fuel flow cooperating with one seat and a cut-off valve for the fuel flow cooperating with the other seat, both of said valves being mechanically controlled from said pressure motor means, said valve device having a passageway leading from the inlet thereof to said rst chamber, said second chamber being subject to the inlet pressure in said valve device, control means independent of both said modulating valve and said cut-oi valve for selectively connecting said iirst chamber to said passageway or to atmosphere, pilot control means operable in response to room temperature changes for operating said control means through said pressure motor means at a predetermined temperature, said pressure motor means thereafter modulating said valve device when the room temperature is below said preden termined temperature.

4. A combination modulating valve and shutoff valve assembly comprising a valve housing having an inlet and an outlet, a modulating valve disposed in said valve housing, a shut-oir valve disposed in said housing, a modulating valve member and a shut-off valve member connected together, a diaphragm secured to said valve members, a pressure chamber having said diaphragm as a movable Wall thereof, a pilot valve for controlling the pressures to and from said pressure chamber, a modulating motor for said modulating valve, and means operated thereby at one of its limits of operation to actuate said pilot valve to eiect opening of said on-oi valve as said modulating motor moves away from its minimum modulated position and to effect closing thereof as it returns to its minimum modulated position.

5. In a mechanism of the kind described, a valve device having an inlet and an outlet, on-off and modulating valve seats between the inlet and an outlet, said on-of seat being toward the inlet and said modulating seat being toward the outlet, walls joining the two seats, a pair of interconnected valve members movable one toward said on-off valve seat While the other recedes from said modulating valve seat, a pressure chamber including a member movable in response to pressure changes, means connecting said movable member with said valve members to move them, one away from said modulating valve seat upon decrease of pressure in said pressure chamber, said movable member, opposite said pressure chamber being subject to inlet preesure to said valve device, a connection joining the pressure chamber to exhaust, means controlling the connections to admit inlet pressure to the chamber to open the valve member relative to on-of seat whereupon the other valve member may effect modulation of the valve after it is opened, and motor means to cause such modulation.

6. A modulating control valve for gas burners comprising a valve having an onnof scat and a modulating seat, valve closure elements for cooperating with said seats, means extending through both seats for connecting said closure elements rigidly together, a diaphragm for supporting said valve closure elements and said means, one side of said diaphragm surrounding on-ol: seat being subject to the gas pressure, a pressure chamber on the other side thereof, a pilot valve for introducing gas under pressure to said pressure chamber or bleeding it therefrom for closing one of said valve closure elements on its onmoil" seat or opening the same, and means for thereafter modulating the other of said valve closure elements relative to said modulating seat comprising a heat motor, and a room thermostat oi modulating type for energizing said heat motor, said heat motor in all positions, except its cold position, energizing said pilot valve for closing said bleed and introducing pressure to said pressure chamber.

References Cited in the file or" this patent UNITED STATES PATENTS Number Name Date 2,285,913 Derrah June 9, 1942 2,381,799 Berkholder Aug. '7, i945 2,490,420 Davis Dec. 6, 1949 2,576,246 Taylor Nov. 27, i 2,611,542 Crum Sept. 23, 1952 

